(I'm not much into Gmini, I'm mostly replying about Rockbox porting in
general)

> How close is the port to completion and usability?

Closer than a few days ago. Still quite far away from being usable as a good
firmware replacment.

> Will it work on all Gmini's?

Possibly - given lots of time and efforts. Nothing happens automatically, but
if enough people join in and help I hope we'll reach there.

I don't know much about Gmini hardware, but it seems the models differ
somewhat and it might be tricky to figure out the differences and work fine on
all of them.

The porting work seems to be focused on the Gmini 120 for starters.

> Is it worth it to go and buy one now or not?

I doubt anyone but you can tell. If you want a working Rockbox on a player
within a month, you shouldn't get a Gmini and not an iRiver.

> Once Rockbox is ported, is it simple to keep updating Rockbox for Gmini and
> Jukebox, or will the Gmini always be playing catch-up, trying to port the
> new features as they come out for the Jukebox line?

A port of Rockbox will make Rockbox run on yet another player. Exactly like
Rockbox already runs on many players already. It does not make it another
Rockbox or a Rockbox that has a separate life or development thread.

Most of the Rockbox code is "generic" and work on all models. Some parts are
only for certain kinds of players (for example with graphical display or with
recording capabilities). Some parts are specific for a single target. etc

If updates to the generic code is made, it then works on all players at once.
If updates are made to target-specific code, then that update is of course
only working for that player and not any other.